A user is reporting they might have a virus, although it might be related to their reinstalling zone alarm. I don't physically have access to the computer though. They are running Windows XP. When they try to launch any program form explorer they get the error:
Windows cannot access the specified device path or file
So obviously they get to their desktop fine, and are able to open new explorer windows. They are unable to open any documents or launch any other programs though. They are running as Administrator and the behavior is the same in Safe Mode.
I did a Google search for this error and there are a lot of occurrences (12,000), but none of them provide a meaningful solution.
I'd suggest the user get a copy of the Windows XP install CD and have them repair the operating system as per this Microsoft Knowledge Base Article: http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/tips/doug92.mspx
While I don't remember encountering the exact error your user is experiencing, this fixed the majority of mysterious OS errors I encountered when supporting XP.
If that doesn't work your next best option is to send them a LiveCD with copies of spybot, AVG, or whatever your company uses run these from the LiveCD.